I'll agree that major engine failure is rarely the reason we get rid of a car. Heck, generally when we send a car to the junk pile in the sky it is because of an accident or because swapping out the alternator costs more than the car is worth.

That's why these people that change their oil very frequently are kidding themselves when they think it will mean a more reliable car. While the engine may benefit some, the internals are incredibly durable. Oil changes don't help prevent the 99.9% of problems we see, and that happen to be unrelated to engine internals.